lintcode|lintcode 174. 删除链表中倒数第n个节点 lintcode174.删除链表中倒数第n个

【lintcode|lintcode 174. 删除链表中倒数第n个节点】难度：容易
1. Description
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174. 删除链表中倒数第n个节点 2. Solution

python
pre_n指向的位置在cur指向位置的前面第n个。
当cur是链表尾部时，pre_n正好是倒数第n个。

""" Definition of ListNode class ListNode(object): def __init__(self, val, next=None): self.val = val self.next = next """class Solution: """ @param head: The first node of linked list. @param n: An integer @return: The head of linked list. """ def removeNthFromEnd(self, head, n): # write your code here if n==1: if head.next is None: return None pre_n = head cur = head for i in range(n): cur = cur.next while cur.next is not None: pre_n = pre_n.next cur = cur.next pre_n.next = pre_n.next.next return head pre_n = head cur = head for i in range(n-1): cur = cur.next while cur.next is not None: pre_n = pre_n.next cur = cur.next pre_n.val = pre_n.next.val pre_n.next = pre_n.next.next return head

3. Reference